Clutch controlled power transmission mechanism for machine tools



1945- H. R. BAGLEY' I 2,370,282

CLUTCH CONTROLLED POWER TRANSMISSION MECHANISM FOR MACHINE TOOLS Filed'Nov. 27, 1945 3 Sheets-Sheet l Feb. 27, 1945. H. R. BAGLEY 2,370,282

CLUTCH CONTROLLED POWER TRANSMISSION MECHANISM FOR MACHINE TOOLS FiledNov. 27, 1945 s Sheets-Sheet 2 N .29 La 3 l it? I I] g I \\\\\\\\\\\\\wI10 0 emaz' Feb. 27, 1945. H. R. BAGLEY 2,370,232

CLUTCH CONTROLLED POWER TRANSMISSION MECHANISM FOR MACHINE TOOLS FiledNov. 27, 1943 3 Sheets-Sheet 3 Patented Feb. 27, 1945 CLUTCH CONTROLLEDPOWER TRANSMIS- SION MECHANISM FOR MACHINE TOOLS Harold Richard Barley.Tile Hill, Coventry, England, assignor to A.

Coventry, England C. Wickman Limited,

Application November 27,1943, Serial No. 512,011 In Great BritainDecember 17, 1942 2 Claims.

The problem underlying this invention is that of interengaging with aminimum of shock the elements of a dog clutch used in the powertransmission mechanism of a machine tool, and particularly a clutchhaving single inter-engaging parts on its two members such that there isonly one position in each rotation at which engagement can be effected.Such a clutch is required for example in a grinding machine used forgrinding the faces of toothed wheels, spline shafts, or the like, whereit serves to effect a detachable driving connection between a source ofmotion, and, say, a slide or work-spindle operating mechanism, where itis essential that the two members of the clutch shall be engageable onlywhen the said members are in a particular angular relationship.

,The object of the present invention is to enable the above requirementto be satisfied in a simple and convenient manner.

In the accompanying sheets of explanatory drawings Figure l is asectional front elevation, and Figure 2 a part sectional plan, of clutchcontrolled power transmission mechanism in accordance with theinvention.

Figure 3 is a section on the line 3-3 of Figure 1.

Figure 4 is a section on the line 4-4 of Figure 1.

I In carrying the invention into effect as shown, I. employ a shaft a(herein termed the main shaft) on which is freely mounted a toothedwheel b which is driven from any convenient source of motion. At oneside of the wheel b is formed or secured a single laterally projectingtooth c, the wheel and its tooth serving as the driving member of a dogclutch. The complementary or driven member d of this clutch is slidablykeyed on the main shaft a, and is provided with a single tooth e forengaging tooth c of the other clutch member. Parallel with the mainshaft a is arranged a lay shaft f. on the lay shaft 1 is freely mounteda toothed wheel 9 which engages the toothed wheel b on the main stuff.a, and which has combined with it any convenient friction clutch h. Thisclutch It may consist of a plurality of friction plates i, which arealternately connected to the toothed wheel g and the lay shaft 2 and onthis shaft is slidably mounted a pressure piece a which by exertingendwise pressure on the friction clutch effects a frictional drivingconnection between the wheel g and shaft I through the clutch plates.Also on the lay shaft i is mounted another toothed wheel m which engagesa further toothed wheel 11 secured to the main shaft a. The toothedwheel m on the lay shaft is connected to this shaft by a unidirectionalclutch o of any convenient form. In the example shown thisunidirectional clutch comprises an annular member p secured on the layshaft 1, and surrounded by an annular recess q in one end of the toothedwheel m, and rollers 1' arranged in recesses s in the annular member andadapted to co-operate under the action of springs t with the peripheralwall of the recess in the toothed wheel. The two pairs of toothed wheelsb, y and 1n,- n are such that the main shaft a can be temporarily drivenby the driving wheel I) through the lay shaft 1 at a slightly slowerrate than the driving wheel.

Any convenient means are employed for sliding the slidable dog clutchmember (1 on the main shaft a and the pressure piece i on the layshaft 1. Thus wemay employ for this purpose a pair of forked members u,v which are slidably mounted on fixed guides 20, :2: arranged parallelwith the shafts a, .f, the forked members being adapted to embrace andengage grooved peripheral portions of the slidable dog clutch member :1and pressure piece 7 respectively. The forked members u, v are actuatedinproper sequence by pressure fluid which is controlled eitherautomatically in response to movements of parts of the machine on whichthe invention is employed, or in response to the attendant, the frictionclutch h being brought into action before the slidable dog clutch memberd is engaged with the other clutch member b, c. The mechanism employedfor actuating the forked members u, o in the example shown consists of apair of coaxial hydraulic cylinders 2, 3, plunger 4, 5 slidable in thecylinders, and a slidable cam plate 8 actuated by the plungers, the camplate being formed with an elongated recess or slot 1 adapted byengagement with rollers 8 or other projections on the forked members tomove the latter in the proper sequence when movement is imparted to thecam plate.

The action of the mechanism above described is as follows:

Let it be supposed that both the dog clutch b-e and the friction clutchh are out of action, and that only the driving wheel b on the main shaft:1 and its associated wheel g on the lay shaft f are rotating. In thiscondition both shafts a, I are at rest. To set the main shaft a inmotion, the friction clutch h on the lay shaft f is first brought intoaction. This has the eifect ofrotatingthemsinshai'tafihroughtheunidirectiwalarraugedparslldwiththemamshartaseecnd clutch o) atasllghtlyslowerratethan the drivtoothed wheel ireely rotatable on the lay shaftingwheelnlnthisconditionthedogclutcnandadaptedtoreeeivemotlonfromtheflrst membersb.candd.eonthemainshaftainterengaged with a minimum of mainshai'taisnowdriventhroughthedogclutoh b-e at its proper speed. and theunidirectional clutch 0 then ceases to be 098111178. At all! stage thefriction clutch in may be put out ofaction.andthenthetwowheelsg.monthelay shaft I rotate idly.

Whilst I have in the foregoing described a successful embodiment of myinvention. I desire it to be understood that my invention is not limitedthereto as subordinate mechanical details may be varied to suitdifferent requirements.

Having thus described my invention what I claim as new and desire tosecure by letters Patent is:

1. Clutch controlled power transmission mechanism comprising thecombination of a dog clutch consisting of a driving member and a drivenmember, a main shaft on which the driving dog clutch member is freelyrotatable and on which the driven dog clutch member is slldebly keyed,means for rotating the driven dog clutch member at a speed slightlyslower than that of the driving dog clutch member. the said means havingin combination a driving toothed wheel assocleted with the driving dogclutch member. a lay shaft actuating the dog and friction clutches.

2. Clutch controlled power transmission mechanism comprising thecombination of a dog clutch consisting of a driving member and a drivenmember each having a single clutch tooth. a main shaft on which thedriving clutch member is freely rotatable and on which the driven dogclutch member is slidably keyed. a lay shaft arranged parallel with themain shaft. a friction clutch mounted on and adapted to impart motion tothe lay shaft. a unidirectional clutch mounted on the lay shaft. gearingthrough which the unidirectional clutch can serve to transmit motionfrom the lay shaft to the main shaft at a speed slightly slower thanthat of the driving dog clutch member. and means for actuating thefriction and dog clutches so that the friction clutch comes into actionbefore the dog clutch.

HARDID RICHARD EAGLE!

